1. Field of the Invention
The present invention relates to a method, system, and program for using operation codes to control a decoder's use of a buffer to generate data from an input data stream into an output data stream.
2. Description of the Related Art
High speed printers require that data be sent fast enough to continuously supply data to the print engines. For instance, high speed printers can print more than 1,000 pages per minute at 600 dpi (dots per inch). Future printers are expected to run faster and at higher (e.g. 1200 dpi) resolutions. The minimum bandwidth to a 1 bit/spot print engine at 600 dpi for 1,000 pages per minute (1,000 pages per minute×min/60 seconds×8.5 inches×11 inches×600 dpi×600 dpi×1 bit) is 561 Mbits/sec. Moreover, 2,000 pages per minute can be achieved by having two print engines, one each for the front and the back of paper and controlling them independently.
Continuous form printers also need data continuously supplied because they often do not stop or slow down gracefully. One way that this is accomplished is to store multiple pages ready for printing. More pages may be stored to make available for printing if the pages are compressed. However, a decoder must decompress pages at a fast enough rate to continuously supply decompressed data to the printer. Decoders store decoded data in buffers. The buffered data is then sent to the printer to render. Sometimes the decoder also uses the buffer as a history buffer.
There is a need in the art for improved techniques to supply compressed data to a printer that can be decompressed at a fast enough rate to supply to the print engines producing output at a high speed.